Method and system for automatically preserving persistent storage

Abstract

Computer-based methods, techniques, and systems for automatically protecting a storage device from unwanted alterations are provided. Example embodiments provide a Disk Access Redirection System, which includes a Redirection Driver, an Available Space Table (“AST”), a Protected Space Redirection Table (“PSRT”), and optionally an Unprotected Space Table (“UST”). The Redirection Driver is installed and registered with the computer operating system so that it can intercept storage device access requests (such as a disk read/write). When a storage access request for a read or write is sent, the request is intercepted by the Redirection Driver, transparent to the code that invokes the storage access request. The Redirection Driver uses the AST, PSRT, and optionally the UST, to allocate available storage space for redirected write requests, redirect write requests for protected areas of the storage device, and redirect read requests when the read request specifies a storage location that has been previously redirected.

1 .- 83 . (canceled) 
     
     
         84 . A method in a computer system for automatically protecting data, the computer system having a storage area on one or more storage devices, comprising:
 determining storage protection level for at least one storage device;   when the protection level indicates that some level of storage protection is desired,
 designating a first storage area on the least one storage device as redirected space; 
 designating a second storage area on the at least one storage device as unprotected space and generating an unprotected space table that stores addresses of the at least one storage device in the unprotected space; 
 designating a third storage area on the at least one storage device as available space and generate an available space table that stores addresses of the at least one storage device in the available space; 
 designating a fourth storage area on the at least one storage device as protected space and generating a protected space redirection table that maps addresses of the at least one storage device in the protected space to addresses in the redirected space; and 
 registering a software redirection driver as an input/output driver and loading the registered redirection driver in a volatile memory of the computer system, the software redirection driver configured to intercept attempted accesses to location in the protected space and redirect the intercepted accesses to the redirected space. 
   
     
     
         85 . The method of  claim 84  wherein the software redirection driver is further configured to intercept, from requesting code that is external to the software redirection driver, a request to modify a location in the protected space of the at least one storage device and instead redirect the intercepted request to modify a location in the redirected space. 
     
     
         86 . The method of  claim 84  wherein the method is performed when the computer system is performing a bootup operation. 
     
     
         87 . The method of  claim 84  wherein the method is performed where the computer system is performing a mount of a new storage device. 
     
     
         88 . The method of  claim 84 , further comprising:
 responsive to an indication to shutdown or reboot the computer system, disregarding data in the redirected space.   
     
     
         89 . The method of  claim 84 , further comprising:
 responsive to an indication to shutdown or reboot the computer system, saving data in the redirected space to the unprotected space.   
     
     
         90 . The method of  claim 84 , further comprising:
 mapping all the available space into the available space table; and   mapping all the unprotected space in the unprotected space table.   
     
     
         91 . The method of  claim 84  wherein the determining protection level for the at least one storage device is determined in response to user input. 
     
     
         92 . The method of  claim 84  wherein the determining protection level for the at least one storage device determines a level of protection that is one of: no protection, partial protection, of full protection. 
     
     
         93 . A computer system for automatically protecting data, comprising:
 a first storage area on at least one storage device designating redirected space;   a second storage area on the at least one storage device designating unprotected space;   a third storage area on the at least one storage device designating available space;   a fourth storage area on the at least one storage device designating protected space;   an unprotected space table that stores addresses of the at least one storage device in the unprotected space;   an available space table that stores addresses of the at least one storage device in the available space;   a protected space redirection table that maps addresses of the at least one storage device in the protected space to addresses in the redirected space; and   a software redirection driver, wherein the redirection driver is registered as an input/output driver and loaded into a volatile memory of the computer system, the software redirection driver configured to intercept attempted accesses to location in the protected space and redirect the intercepted accesses to the redirected space.   
     
     
         94 . The system of  claim 93  wherein the software redirection driver is further configured to intercept, from requesting code that is external to the software redirection driver, a request to modify a location in the protected space of the at least one storage device and instead redirect the intercepted request to modify a location in the redirected space. 
     
     
         95 . The system of  claim 93  wherein allocations of the storage device into the first, second, third, and forth storage areas are performed upon boot up. 
     
     
         96 . The system of  claim 93  wherein allocations of the storage device into the first, second, third, and forth storage areas are performed upon mount of a new storage device. 
     
     
         97 . The system of  claim 93  wherein responsive to an indication to shutdown or reboot, the computer system disregards data in the redirected space. 
     
     
         98 . The system of  claim 93  wherein responsive to an indication to shutdown or reboot, the computer system saves data in the redirected space to persistent storage. 
     
     
         99 . The system of  claim 93 , further comprising:
 an available space table that maps the available space; and   the unprotected space table that maps the unprotected space.   
     
     
         100 . The system of  claim 93 , further comprising:
 a protection level configured to designate protection of the at least one storage device, wherein the protection level is at least one of unprotected, partially protected, or fully protected.   
     
     
         101 . The system of  claim 93  wherein storage device is arranged according to an architecture that provides files within a cluster framework that provides read and write accesses according to sector number within a cluster of the cluster framework. 
     
     
         102 . The system of  claim 93  wherein the storage device is arranged according to an architecture that provides virtual clusters.